The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Siberia’.
‘Siberia’ is a product of a planned breeding program, which had the objective of creating Zantedeschia hybrids for pot flower production in a wide range of colors with a large, classic flower shape. The breeding program began in 1989, and the new cultivar is a seedling selected from the crossing of Zantedeschia sprengeri ‘Z010448’ with a Zantedeschia sprengeri variety Chrystal Blush (male parent, unpatented). ‘Siberia’ was selected in 2006 by the inventor in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Siberia’ by tissue culture was performed by the inventor in September of 2008 in 't Zand, The Netherlands. Subsequent asexual reproductions by tissue culture at the same location have demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown in a 14 cm pot at 12-14 weeks after planting in 't Zand, The Netherlands under greenhouse conditions, which approximate those generally used in horticultural practice. Color references are made to The 2001 R.H.S. Colour Chart of The Royal Horticultural Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to be basic characteristics of ‘Siberia’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. White-colored spathe;        2. White linear spots in leaves; and        3. High inflorescence production.        
Further, when compared to calla lily plant named ‘Sapporo’ (unpatented), the upper and lower surface spathe color of ‘Sapporo’ is White Group RHS 155C, while the upper surface spathe color of ‘Siberia’ varies between White Group RHS 155B and Green-White Group RHS 157C and the lower surface spathe color of ‘Siberia’ varies between Yellow-Green Group RHS 150B and 150C. Further, ‘Sapporo’ has from 3-6 branches, while ‘Siberia’ has from 3-10 branches. Additionally, ‘Siberia’ exhibits more numerous leaf maculation spots than ‘Sapporo’.
Table 1 provides similarities and differences of ‘Siberia’ to its parents, Zantedeschia sprengeri ‘Z010448’ and variety Chrystal Blush.
TABLE 1‘Siberia’SimilaritiesDifferencesZ010448Spathe sizeSpathe color (Varies between Yellow-WhiteGroup RHS 158A and 158C)Plant heightChrystal BlushLeaf shapeNumber of inflorescences (5-15)Plant heightSmaller spathe sizeNo spots on leaves